1. Field
The present disclosure relates to a device for supplementing a voice, and for example, to a device for supplementing a voice that generates a vibration for sound by attachment to or contact with a body and a method for controlling the device.
2. Description of Related Art
A sound of human beings is expressed through a voice. The voice generated by vocal organs is classified into: a pronunciation or a speech sound for communication of linguistic transinformation; and a non-linguistic vocalization irrelevant to communication. While a sound of animals without a vowel is differently felt by a listener according to his own thought, a voice of human beings with a vowel constitutes various discriminable sounds. As a result, human beings communicate with one another by the voice.
The voice of human beings is an essential element for communication, and various vocal organs of a nervous system and a respiratory system relate to generation of the voice. Among the nervous system, a central nervous system and a peripheral nervous system relate to generation of the voice. A cranium or a nucleus of a brain cell which is necessary for generation of language is disposed in a brain stem of the central nervous system. A cerebellum of the central nervous system has a function of tuning a control of muscle for operation, and a cerebral hemisphere of the central nervous system performs a dominant role in language function. There are the fifth brain nerve relating to movement of a chin, the seventh brain nerve relating to movement of lips, the tenth brain nerve relating to movement of a pharynx and a larynx, the eleventh brain nerve relating to movement of a pharynx and the twelfth brain nerve relating to movement of a tongue in a cranial nerve relating to generation of the speech sound. A nersus laryngeus superior and a recurrent laryngeal nerve of the peripheral nervous system which are separated from a vagus nerve directly relate to movement of the larynx.
The speech sound is generated by an intimate interaction among a lower respiratory system, a larynx and a vocal track. Specifically, the larynx in a neck of human beings which relates to a voice is disposed between second and third cervical vertebrae (C2, C3) when one is a baby and moves to be disposed between third and sixth cervical vertebrae (C3, C6) when one is an adult. The larynx has functions of swallowing, cough, occlusion, respiration and vocalization. Specifically, the larynx includes a vocal cord as a source of a voice. The vocal cord has a wrinkled double-layered shape crossing an inner space of the larynx. A flow of an expired air vibrates the vocal cord and a control of the expired air efficiently supplies a sound energy during vocalization. When the vocal cord is properly strained and closed, the expired air vibrates the vocal cord, and a glottis that is a gap between the vocal cord and an arytenoid of the larynx opens and closes with a specific period to cut and connect the expired air. The discontinuous flow of the expired air functions as the source of the voice. When the air expired to exterior by respiration passes though the glottis, the air vibrates the vocal cord. Although the sound generated in the larynx is a consonant, a vowel is generated by means of a palate, a tongue, teeth and lips.
A voice disability may be defined as a problem such that a pitch, a loudness, a quality and a flexibility of a voice are not proper to a gender, a physique, a social environment and a geographical position. The innate or acquired voice disability may be cured by a surgery of expanding or reducing the vocal cord of the larynx. However, the voice disability is not completely cured and an effect of the surgery is not accurate. Various methods for determining the voice disability, for example an investigation of voice symptom, an investigation of voice usage pattern, an acoustic test and aerodynamic test, have been developed, and whether the voice disability exists or not is determined by the various methods to a certain extent.
The voice disability having various types is classified into a functional voice disability and an organic voice disability. Most of voice disabilities may result from a disability of the vocal cord, and the disability of the vocal cord may be caused by generation of a tumefaction, a tearing or an abnormal substance due to an external environmental factors.
For the purpose of overcoming the voice disability, an artificial vocal cord has been suggested. In a method of using the artificial vocal cord, an artificial connecting tube is inserted between a respiratory tract and an esophagus so that the air of the respiratory tract can be induced to the esophagus and can vibrate an esophageal sphincter instead of the vocal cord. When the esophageal sphincter vibrates, a flow of the air remaining in the respiratory tract is cut so that vocalization can be performed. However, the voice by the artificial vocal cord has a poor quality to have a mere conversation. Accordingly, a number of troubles in a social life are still not surmounted.
Besides the vocal disability, people suffer from a vocal disorder such that vocalization is not controlled due to an uncontrollable voice. For example, a voice may be too loud, too quiet or too hoarse. Although the surgery of the larynx or the vocal cord is performed to overcome the vocal disability or the vocal disorder, the curing method is not a perfect solution because the surgery is sometimes impossible.